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Dr Amr Elheny Assistant professor of general surgery Blunt Abdominal Trauma: Evaluation

Blunt Abdominal Trauma: Evaluation

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Page 1: Blunt Abdominal Trauma: Evaluation

Dr Amr Elheny

Assistant professor of general

surgery

Blunt Abdominal Trauma:

Evaluation

Page 2: Blunt Abdominal Trauma: Evaluation

Outline

Anatomic definition of abdomen

Mechanisms of injury in blunt trauma

Typical injury patterns

Assessment of blunt abdominal trauma

Diagnostic algorithms

Page 3: Blunt Abdominal Trauma: Evaluation

Abdomen: anatomic boundaries

External: Anterior abdomen: transnipple line superiorly, inguinal ligaments and

symphasis pubis inferiorly, anterior axillary lines laterally.

Flank: between anterior and posterior axillary lines from 6th intercostals space to iliac crest.

Back: Posterior to posterior axillary lines, from tip of scapulae to iliac crests.

Internal: Upper peritoneal cavity: covered by lower aspect of bony thorax. Includes

diaphragm, liver, spleen, stomach, transverse colon.

Lower peritoneal cavity: small bowel, ascending and descending colon, sigmoid colon, and (in women) internal reproductive organs.

Pelvic cavity: contains rectum, bladder, iliac vessels, and (in women) internal reproductive organs.

Retroperitoneal space: posterior to peritoneal lining of abdomen. Abdominal aorta, IVC, most of duodenum, pancreas kidneys, ureters, and posterior aspects of ascending and descending colon.

Page 4: Blunt Abdominal Trauma: Evaluation

Mechanisms of injury

Compression, crush, or sheer injury to abdominal viscera

deformation of solid or hollow organs, rupture (e.g. small

bowel, gravid uterus)

Deceleration injuries: differential movements of fixed and

nonfixed structures (e.g. liver and spleen lacs at sites of

supporting ligaments)

Page 5: Blunt Abdominal Trauma: Evaluation

Common injury patterns

In patients undergoing laparotomy for blunt trauma, most frequently injured organs are spleen (40-55%), liver (35-45%), and small bowel (5-10%). (ATLS, 2001)

Duodenum:

Classically, frontal-impact MVC with unrestrained driver; or direct blow to abdomen.

Bloody gastric aspirate, retroperitoneal air on XR or CT

Confirmed with upper GI series or double contrast CT

Small bowel injury:

Generally from sudden deceleration with subsequent tearing near fixed points of attachment.

Often associated with seat belt sign, lumbar distraction fracture (Chance fracture)

DPL superior to FAST or CT for diagnosis.

Page 6: Blunt Abdominal Trauma: Evaluation

Common injury patterns (2)

Pancreas: Direct epigastric blow compressing pancreas against vertebral column.

Early normal serum amylase does NOT exclude major pancreatic trauma.

CT with PO/IV contrast – NOT particularly sensitive in immediate post-injury period.

Diaphragm: Most commonly, 5-10 cm rupture involving posterolateral hemidiaphragm.

Noted on CXR: blurred or elevated hemidiaphragm, hemothorax, GT in chest

Genitourinary: Anterior injuries (below UG diaphragm): usually from straddle impact.

Posterior injuries (above UG diaphragm): in patient with multisystem injuries and pelvic fractures.

Page 7: Blunt Abdominal Trauma: Evaluation

Common injury patterns (3)

Solid organ injury

Laceration to liver, spleen, or kidney

Injury to one of these three + hemodynamic instability: considered indication for urgent laparotomy

Isolated solid organ injury in hemodynamically stable patient: can often be managed nonoperatively.

Pelvic fractures:

Suggest major force applied to patient.

Usually auto-ped, MVC, or motorcycle

Significant association with intraperitoneal and retroperitoneal organs and vascular structures.

Page 8: Blunt Abdominal Trauma: Evaluation

Restraining devices

Lap seat belt Mesenteric tear or avulsion

Rupture of small bowel or colon

Iliac artery or abdominal aorta thrombosis

Chance fracture of lumbar vertebrae (hyperflexion)

Shoulder Harness Rupture of upper abdominal viscera

Intimal tear or thrombosis in innominate, carotid, subclavian, or vertebral arteries

Fracture or dislocation of C-spine

Rib fractures

Pulmonary contusion

Air Bag Corneal abrasions, keratitis

Abrasions of face, neck, chest

Cardiac rupture

C or T-spine fracture

Page 9: Blunt Abdominal Trauma: Evaluation

Assessment: History

Mechanism

Symptoms, events, PMH, Meds, EtOH/drugs

MVC:

Speed

Type of collision (frontal, lateral, sideswipe, rear, rollover)

Vehicle intrusion into passenger compartment

Types of restraints

Deployment of air bag

Patient's position in vehicle

Page 10: Blunt Abdominal Trauma: Evaluation

Assessment: Physical Exam

Inspection, auscultation, percussion, palpation

Inspection: abrasions, contusions, lacerations, deformity

Grey-Turner, Kehr, Balance, Cullen

Auscultation: careful exam advised by ATLS.

(Controversial utility in trauma setting.)

Percussion: subtle signs of peritonitis; tympany in gastric

dilatation or free air; dullness with hemoperitoneum

Palpation: elicit superficial, deep, or rebound tenderness;

involuntary muscle guarding

Page 11: Blunt Abdominal Trauma: Evaluation

Physical Exam: Eponyms

Grey-Turner sign:

Bluish discoloration of lower flanks, lower back; associated with retroperitoneal bleeding of pancreas, kidney, or pelvic fracture.

Cullen sign:

Bluish discoloration around umbilicus, indicates peritoneal bleeding, often pancreatic hemorrhage.

Kehr sign:

L shoulder pain while supine; caused by diaphragmatic irritation (splenic injury, free air, intra-abd bleeding)

Balance sign:

Dull percussion in LUQ. Sign of splenic injury; blood accumulating in subcapsular or extracapsular spleen.

Page 12: Blunt Abdominal Trauma: Evaluation

Diagnostic adjuncts

Labs: BMP, CBC, coags, b-HCG, amy/lip, U/A, tox screen,

T&C

Plain films: CXR, pelvis; abd films generally lower priority

DPL

FAST

CT

Page 13: Blunt Abdominal Trauma: Evaluation

Diagnostic Peritoneal Lavage

98% sensitive for intraperitoneal bleeding (ATLS)

Open or closed (Seldinger); usually infraumbilical, but may be supraumbilical in pelvic frxs or advanced pregnancy.

Free aspiration of blood, GI contents, or bile in demodynamically abnormal pt: indication for laparotomy

If gross blood (> 10 mL) or GI contents not aspirated, perform lavage with 1000 mL warmed LR. Allow to mix, compress abdomen and logross paient, the sent to lab. + test: >100,000 RBC/mm3, >500 WBC/mm3, Gram stain with bacteria.

Alters subsequent examination of patient

Has been somewhat superceded by FAST in common use; now generally performed in unstable patients with intermediate FAST exams, or with suspicion for small bowel injury.

Page 14: Blunt Abdominal Trauma: Evaluation

FAST: Strengths and Limitations

Strengths

Rapid (~2 mins)

Portable

Inexpensive

Technically simple, easy to train (studies show competence can be achieved after ~30 studies)

Can be performed serially

Useful for guiding triage decisions in trauma patients

Limitations

Does not typically identify source of bleeding, or detect injuries that do not cause hemoperitoneum

Requires extensive training to assess parenchyma reliably

Limited in detecting <250 cc intraperitoneal fluid

Particularly poor at detecting bowel and mesentery damage (44% sensitivity)

Difficult to assess retroperitoneum

Limited by habitus in obese patients

Page 15: Blunt Abdominal Trauma: Evaluation

FAST: Accuracy

For identifying hemoperitoneum in blunt abdominal trauma:

Sensitivity 76 - 90%

Specificity 95 - 100%

The larger the hemoperitoneum, the higher the sensitivity. So sensitivity increases for clinically significant hemoperitoneum.

How much fluid can FAST detect?

250 cc total

100 cc in Morison’s pouch

Page 16: Blunt Abdominal Trauma: Evaluation

Does FAST replace CT?

Only at the extremes.

Unstable patient, (+) FAST OR

Stable patient, low force injury, (-) FAST consider observing patient.

CT is far more sensitive than FAST for detecting and characterizing abdominal injury in trauma. The gold standard for characterizing intraparenchymal injury.

“Death begins with a CT.” Never send an unstable patient to CT. FAST, however, can be performed during resuscitation.

Page 17: Blunt Abdominal Trauma: Evaluation

CT

EAST level I recommendations (2001):

CT is recommended for evaluation of hemodynamically

stable patients with equivocal findings on physical

examination, associated neurologic injury, or multiple

extra-abdominal injuries.

CT is the diagnostic modality of choice for nonoperative

management of solid visceral injuries.

Page 18: Blunt Abdominal Trauma: Evaluation

EAST Algorithm: Unstable

Eastern Association for the Surgery of Trauma, 2001

Page 19: Blunt Abdominal Trauma: Evaluation

EAST Algorithm: Stable

Eastern Association for the Surgery of Trauma, 2001

Page 20: Blunt Abdominal Trauma: Evaluation

References

Hoff et al. EAST Practice Management Guidelines Work Group. Practice Management Guidelines for the Evaluation of Blunt Abdominal Trauma, 2001. www.east.org.

American College of Surgeons Committee on Trauma. Advanced Trauma Life Support for Doctors; Student Course Manual, 7th edition, 2004.

Scalea TM, Rodriquez A, Chiu WC. Focused Assessment with Sonography for Trauma (FAST): Results from an International Consensus Conference. J. Trauma 1999;46:466-472.

Yoshii H, Sato M, Yamamoto S. Usefulness and Limitations of Ultrasonography in the Initial Evaluation of Blunt Abdominal Trauma. J. Trauma 1998;45:45-51.